Electro-mechanical relays



J. A. DREYFUS 2,775,671

ELECTRO-MECHANICAL RELAYS Original Filed Nov. l0, 1948 5 Sheets-Sheet l Dec. 25, 1956 ab` SVM@ Dc'fgs 9 4--g DCU@ Dec. 25, 1956 J. A. DREYFUS 2,775,671

ELECTRO-MECHANICAL RELAYS Original Filed Nov. l0, 1948 Fig. 6

5 Sheets-Sheet 2 INVENTOR.

Dec. 25, 1956 J. A. DREYFUS 2,775,671

` ELECTRO-MECHANICAL RELAYS Driginal- Filed Nov.- 10, 1948 5 Sheets-Sheet 3 IN V EN TOR.

United States Patent O ELECTRO-MECHANICAL RELAYS Jean Albert Dreyfus, Geneva, Switzerland Original application November 10, 1948, Serial No. 59,361. Divided and this application September 19, 1952, Serial No. 310,513

6 Claims. (Cl. 200-166) This invention relates to suspension elements for electro-mechanical relays and it is an object of the present invention to improve the construction and the operation of such elements.

The present application is a division of my co-pending application Serial No. 59,361, iiled November l0, 1948 now Patent No. 2,661,412, December 1953.

Known electro-mechanical relays generally comprise a movable armature which is suspended by a device such as a pivot and which executes a rotary movement under action of magnetic fields. The field is produced by an operating electric current. By its movement the movable armature opens or closes one or more contacts of controlled electric circuits.

According to the present invention the movable armature is suspended by means of a plurality of parallel lamellar springs arranged radially around the centre of the armature. Thus, in place of rotary movements the armature carries out parallel (translatory) movements under the action of the magnetic iields. The mounting is free from external friction or play. The opposing force produced by the lameller springs can be strictly proportional to the longitudinal displacement of the armature. The neutral position of the movable armature can remain exactly constant. The arrangement according to the invention can improve known electro-mechanical relays which comprise a movable ferro-magnetic armature which moves under the action of electric iields generated by a xed coil. These relays are known in telephone or telegraphic systems, for bells, vibrators, electric-mechanical rectiers and for other purposes. Further, the arrangement according to the invention also permits the construction of completely novel electro-dynamic relays comprising a movable coil which is transversed by the operating current and which is suspended in the air gap of a fixed electro-magnet or permanent magnet.

By way of example Figures l to 23 illustrate some arrangements according to the invention.

Figure l is a section through a relay having a movable armature which is suspended by springs having the form of bent lamellae.

Figure 2 is a view of suspension springs of Figure l;

' Figures 3 and 4 are detail views of parts of Figure 1;

Figure 5 shows a modification of the arrangement according to Figures l to 4;

Figure 6 is a section through a relay comprising a movable armature the suspension springs of which constitute electrical conductors;

Figures 7 and 8 are detail views of parts of the relays of Figure 6;

Figure 9 shows a modification of a part of the relay of Figure 7;

Figures l0 and ll show in section and in plan a movable armature which comprises a coil and which is applicable to all the relays described;

Figures 12 and 13 show in plan and in section a ilexible electrical conductor which is formed with two bent larnellae and which constitutes an improved suspension arrangement;

Figures 14 and 15 are schematical axial views of such conductors;

Figures 16 and 17 illustrate diagrammatically the mechanical operation;

Figure 18 shows diagrammatically the force as a function of the displacement;

Figures 19 to 22 are plan and sectional views of parts of a relay having the improved arrangement illustrated in Figures l2 to 18.

Figure 23 is a section through an electro-magnetic relay provided wit-h suspension springs like those of Figures 12 to 18.

According to Figure l the permanent magnet 31 produces a uniform magnetic eld in the annular air gap provided between the cylindrical core 32 and the pole ring 33. The movable coil comprises a cylindrical body 34 which is formed with two grooves in which are located two windings 35 and 36. Details of construction are shown to a larger scale in Figures l() and l1. The coil is suspended by a group of at least two spring strips 38 to 40 which may be made of bronze and which are arranged radially symmetrically and in arcs of a circle. Each strip can be formed with a circular slot 41 in which a screw 42 is slidably mounted, this permitting the adjusment of the resilient force of the springs. The ends of the 'windings 35 and 36 are soldered to lsplit terminals such `as `44 Iby means of flexible conductors 45. The displacements of the movable coil lare transmitted to insulating discs l46 and I47 by means lof the shaiit 48 which is held in the coil by the split sleeve `49, the ring 50 and the -screw Sil. The discs y46 .andl 47 carry movable contacts such as 52 to 55 which are connected to external termin-als 56 to 5-9 by means -of at least two radially Iand symmetrically arranged bent metallic strips such :as 61 to 64 (Figure 3). The 'terminals `56 to 59 are gripped -between pairs of insulating 4rings such as `66, `67 and 68, 169. When the movable coil is traversed by an operating -current 4the movable contacts 52 to 55 come against lthe spring contacts such asr 711 to 7-4 of the controlled circuits (Figure 4). These springs yare clamped between insulating rings such 'as 75 to 78. All the Iinsulating rings can be assembled `one on the other with the aid of three insulating Iscrews 81 to 83 and clamped 'together by 4nuts such as 84. The ends of the liexible leads and of the springs are connected to axially external cables such as and 76 which are clamped `between the discs 87 Iand 88 by screws such as 89. A movable cover such as 90 protects the relay.

In 4the arrangement Iaccording to Figure 5 movable contacts can be riveted on leaf springs such as 91 to 94 and they are adapted to engage spring contacts 95, 96, or 97, 98 Iwhen the operating rod 99 is displaced by the movable coil.

In the arrangement @according `to Figures 6 Ito 8 and also according to Figure 9, the suspension springs of the movable coil |101 are constituted by bent metallic strips such as 102 `and 1103 which connect electrically the movable contacts such as 104 and 105, lwhich are gripped between insulating discs 106 and 107, to external terminals such as 108 and 109. yParts lof these strips such as 110 to 113 can serve t-o Isupply the movable coil, thus econom-ising in the use of special llexible conductors while providing an improved form of construction. The movable contacts are adapted to engage against radial yspring contacts such as 1'1'4 to 121. The movable shaft 122 can be supported by two spring arrangements, one of which including bronze strips such -as 102 4and 103 is elastic while the other, which includes strips such as 123 and 1:24 of annealed copper, aluminum or other soft metal, provides supplementary damping.

The bent strips can have shapes such as those shown at 125 in Figure 9.

The insulating members, such as the ring 141 and the discs 142vand 87 in Figurel l or the ringf 143zand the disc 144 in Figure 6, electrically insulate the armature-v such as 32 Vand 33 and the magnet such as 31 from the earth. Thus, the windings of the movable coil such as .35, 3,6 could be energised by a currentfderived from a highv tension supply such as an anode supply without risk of electrical discharge in the gap. The armatures could' be isolated in the air or they could be brought to the mean potential ot the movable coil.

In the arrangement according to Figure 10 the body of the coil 34 could be formed from a cylinder of non-magnetic metal such as brass or aluminium. By a suitable choice of the electrical conductivity of the metal and the thickness of the walls it is possible to obtain any desired damping of the movable assembly by the action of the induced currents. Moreover, the metal cools the windings so that the permissible current density is many times greater than in the case of coils having bodies made of insulating material.

To obtain a relay which makes impulsive oscillations two symmetrical permanent magnets such as the rings 131 and 132 are introduced into the body of the coil. Each time that the windings receive an impulse in the reverse direction the movable armature passes its position of equilibrium and permanenlty closes a set of opposing contacts.

The two symmetrical windings such as 3S and 36 could be connected in series, in parallel or in push-pull. They can be of high or low resistance varying between a few ohms and some thousands of ohms according to the characteristics of the controlling circuit.

A numerical example of an electro-dynamic relay which is shown in full scale in Figures l to 9:

"eight of magnet 150 grammes. Weight of armatures 150 grammes. Weight of the movable assembly 5 grammes.

Axial force of the coil F: 8,000 (gauss) X31-LX 2(0m.) X2,000(turns) 0.05 (amperes) 0.1 (C. G. S.) :500,000 dynes :450 grammes.

Voltage 70 volts. Power 0.0.3(an1peres) X70(\0lts) :3.5 watts.

For 20 Contact springs per section, force per contact-20 grammes.

Opposmg force of the diaphragm o0 grammes for displacement of 0.5 mm.

Time

llisec Thickness of the conducting strips l mi (123, 124` 116. and 117 of Figure 6) forming the diaphragms:0.07 mm. (bronze or brass).

Total number of contacts 4X20z80.

The above arrangement permits of the energising of two coil windings and the polarised operation of thirty-six independent circuits.

' It is possible to utilise condensers to obtain the selective operation according to frequency or impulses. A second symmetrical relay could be connected with the shaft 145 (Figure 6) passing through an opening in the coil to obtain a push-pull magneto-mechanical arrangement.

Inl order that different types of relay may be mounted with the aid of standard interchangeable elements the clamping rings such as 104 and 105 of Figure 6 can be made of moulded material having recesses and holes to receivek projections stamped in the strips such as 125 of Figure 9. Similarly, the insulating disc such as 107 (Figures 6 and 10) can be formed with holes lin which the contacts such as 133 can tit and from which they can project. In these conditions only the silver contacts such as 133 and 134 are riveted to their strips, while the strips themselves can be fitted or removed simply by unscrewing the rings such as 131 and 132 or 104 and 105. Thus it is possible to fit n-l-2 strips in each pair of rings, the strips being arranged evenly in the form of a star, whereby 11:1, 2, 3, 4.

In the case of vibratory or oscillatory electrodynamic relays it is an advantage to avoid the damping caused by the annular metal body of the coil while maintaining the coolingproperties of the metal. In this case an axial slot is cut in the cylinder of the body of the coil underneath the windings.

By varying the length of the slot or by cutting a number of axial holes it is possible to vary as desired the damping co-ecient of the body of the coil. For the same purpose it is also possible to vary the thickness of the cylinder wall.

To utilise the relay as a transformer or vibrator to convert a direct current into an alternating current, whether single phase or polyphase, the controlling and controlled circuits are connected in series, one or more rest contacts being provided which are adapted to close in a phase displacing manner. With the aid of electrical condensers it is possible to synchronise the mechanical resonance with the electrical resonance. The group of bent strips of Figure 2, the strength of which is adjustable, enables the mechanical resonance to be adjusted. Such vibratory relays can also be utilised as motors of clocks or the like or as bells or the like.

The relay according to the invention with its standard interchangeable elements is capable.` of the most Varied uses. It can advantageously be used to replace the known electromagnetic relays in telephoney and in telecontrolled systems and also the impulse relays of selectors, controllers, rocking relays, permanent relays whether having a delayed or instantaneous action and polarised relays for` high speed telegraphy. Further'- more, when the relay is connected to provide self maintained oscillations it can serve to generate musical frequencies, as an accurate clock motor, as a vibrator, as a rectifier, as a warning signal or for other purposes.

The supporting conductors described can be considerably improved when the axis of each conductor describes 2n half-loops connecting Zn-i-l straight segments which whenat rest, are situated in a plane which is approximately normal to the direction of movement of the movable armature, where n is a whole number, such as l, 2, 3 etc. This conductor provides 2 (2n-H) parallel pivotal axes which `are free from play and from external friction and it produces a restoring force which is proportional to the displacement of the armature over wide limits.

According to Figures l2 to 14 the spring strip, which may be of bronze, aluminium or of another metal, comprises a fixed end 1 secured to a xed insulator and a movable end 2 attached to an insulator 3 which carries out translatory movements under the effect of the force Fi. The mean longitudinal axis of the spring conductor comprises threestraight segments ftto 6 and two half loops 7 and 8 which are in opposite directions. The ends are connected by four quarter loops which cancel out the lateral staggering. The electric current flows through the conductor in the direction of the parallel arrows 9 and 11 and of the oppositely-directed arrow 10. The self-induction of this double loop conductor is much less than that of a coiled conductor, this being particularly advantageous with high amperage currents or with high frequencies.

The width b of the conductor is at least ten times greater than its thickness e. The total width g is much less than the distance d between the two ends. Thus, the conductor is resiliently flexible when it is acted upon byk a force F1 normal to its axial plane while it resists any other force,l such as F2 or Fa, situated in this plane.

The mechanical operation of the conductor is represented by the two plan views of Figures 16 and 17. Everything acts as if the conductor comprises five rigid rods 1 and 2 and 4 to 6 connected by six pivotal connections which are free from play and which correspond to four pivots 14 to 17 having parallel axes. The movable end is thus acted upon by two incorporated opposing springs 18 and 19. Thus, when the insulator 3 is acted upon by a force -l-Fi the conductor introduces an opposing force F1 which, Within wide limits, is strictly proportional to the elongation e1 caused by the movement of the movable end, as is shown in the diagram of Figure 18.

To increase the number of contacts of an electro-dynamic relay, while improving the mounting of the movable coil, it is possible, according to Figures 19 to 22, to provide a certain number, such `as 3, 4, 6, 8, 12, 24 or more, conductors, such as 222, 223, 234, 235, arranged in the form of a star. Their movable ends are clamped between insulating disc 239 and 240, while their xed ends are riveted to an insulating ring 231. The contacts of the movable conductors are adapted to engage the springs 236 and 239 when the movable coil is inuenced by a predetermined change in the current through it.

According to Figure 21 a conductor such as 223 to 234 is contained within a surface which is limited by a sector of a circle with radii 241 and 242. The straight sections of the longitudinal axis of the conductor are arranged radially. Thus it is possible to provide a great number of conductors in the form of a star so as to make the best use of the space available. It is also possible to arrange a plurality of star-like assemblies of conductors in the manner of the spokes of a bicycle wheel in order to increase the number of contacts.

The movable coil can be replaced by a ring of a magnetic metal, such as soft iron, steel or a magnet and the permanent magnet can be replaced by an electro-magnet the winding of which is traversed by the varying current.

Two or more star assemblies of conductors according to the invention may be arranged, when at rest, in parallel planes.

Thus, Figure 23 shows an electro-magnetic relay comprising a movable armature 251 which is mounted in the gap formed between the lixed armatures 252 and 253 and in which the magnetic eld is produced by the xed coil 254.

The suspension, the centering and the guiding of the movable armature are elfected by conductors such as 255 to 258 which are disposed in the form ofa star and which are similar to the conductors 222. The contacts of these conductors are adapted to engage against spring contacts `such as 259 to 262.

By way of another example Figure 15 shows the longitudinal `axis of a supporting conductor which includes four half-loops 161 to 164 and ve straight sections 6 to 169. The number of internal pivotal axes is then 10.

What is claimed is:

l. A suspension element for a movable member, said element comprising a ilexible elastic blade having a fixed end and another end adapted to be connected to said movable member, said blade extending when at rest in one plane which is substantially perpendicular to the direction of movement of said movable member and having rectangular portions extending in said plane and separated by elongated slots formed in the blade, the width of the blade being greater than its thickness and smaller than its length, said rectangular portions forming 2n half loops joining 2n-i-1 straight sections, wherein n=1,2,3,4

2. An element in .accordance with claim l, wherein said slots overlap each other but do not contact each other.

3. An element in accordance with claim 2, wherein said slots extend substantially parallel to each other.

4. A suspension element for a movable member, said element comprising a flexible elongated conductor having a lixed end and another end adapted to be connected to said movable member, said conductor having a longitudinal axis forming 2n half loops joining 2n-1-1 straight sections, wherein n=l,2,3,4 said conductor extending when at rest in `a plane which is substantially perpendicular to the direction of movement of said movable member, said other end being in alinement with said fixed end, said longitudinal axis further having quarter loops connected to said ends, whereby the shifting of said straight sections caused by said half loops is compensated.

5. A suspension element for a movable member, said element comprising two elastic conducting blades extending parallel to each other, each blade having a iixed end and ianother end adapted to be connected to said movable member and comprising a plurality of radially disposed portions extending in the same plane.

6. A suspension element for a movable member, said element comprising a flexible elongated conductor having a xed end and another end adapted to be connected to said movable member, said conductor having the shape of a sector of a circle and having a longitudinal axis forming 2n half loops joining 2n+1 straight sections, said straight sections constituting radii of said circle, whereby n=1,2,3,4 said conductor extending when at rest in a plane which is substantially perpendicular to the direction of movement of said movable member.

References Cited in the tile of this patent UNITED STATES PATENTS 1,932,164 Petit Oct. 24, 1933 2,585,278 ShiVers Feb. 12, 1952 FOREIGN PATENTS 144,411 Switzerland Mal'. 16, 1931 

